Medicine dropper



Sept. 8, 1953 M. R. FIELDS MEDICINE DROPPER Filed oct. 4. 195o PatentedSept. 8, 1953 MEDICINE DROPPER Mack R. Fields, Libertyville, Ill.,assignor to Abbott Laboratories, North Chicago, Ill., a corporation ofIllinois Application October 4, 1950, Serial No. 188,423

7 claims. l

This invention relates to medicine droppers and more particularly toone-piece medicine droppers having a positive discharge control.

Generally, the medicine droppers of the prior art are made with a glasspipette and a rubber bulb. The parts of such droppers must bemanufactured with very close tolerances, as the bulb is frictionallyheld on the pipette, and a loose iitting bulb would fail to supply thenecessary pumping action to draw liquid into the pipette. If such arubber bulb dropper is used with oil, as for instance, iish liver oil,care must be taken by the user so that no oil gets into the rubber bulb,as the rubber parts deteriorate very rapidly in contact with oil.

According to the present invention, a medicine dropper is provided, madeof a resilient, heat scalable plastic which is impervious to oil, and adropper assembly which is a one-piece bulb and dropper combination. Thedevice, also, serves as a cap liner as well as a medicine dropper.

Referring to the drawings:

Figure 1 is a vertical section of a complete medicament package,including a dropper assembly according to the invention;

Figure 2 is an enlarged section of the bulb and adjacent parts; and

Figure 3 is a top plan view of the parts shown in Figure 2.

In the embodiment of the invention selected for illustration, aconventional bottle I is provided with screw threads I2 to co-operatewithV a conventional annular Bakelite screw iitting I4. The screw ttingI4 has a large central opening peripherally defined by a narrow inwardlydi rected ange I6 which overlies the edge of the bottle neck I8. Thedropper proper includes a slightly tapered pipette section 20 having atop flange 22.

The dropper proper is completed by the cap, indicated as a whole byreference character 24, which cap comprises a base annulus 26 ofconstant inside diameter and a somewhat thinner dome 28 which issubstantially a portion of a perfect sphere subtending an angle of about120 with respect to its own center of curvature. A gently tapered zone38 joins the base annulus 26 and the dome 28.

The outer surface of the annulus 26 is provided with a shallow groove32, and below the groove I provide an outwardly directed flange 34. 'Iheshoulder at the top of the shallow groove 32 is of such radialdimensions that the iitting I4 can be pushed down from the top and snapinto place.

The flange 22 of the pipette is illustrated as continuing outwardly toabout the inner diameter of the bottle neck I8, and then sloping upwardgently as indicated at 36 to end in a narrow peripheral lip 38 of thesame outside diameter as the liange 34. Juxtaposing the pipette and capand applying heat to the portion 38 and the outer edge of the liange 34easily fuses the pipette and dome into a single unitary dropper withoutsubstantial alteration of the external conguration of the assembly. Y

The slight shoulder along the inner edge of the inclined portion 3Bdenes a contact member suiiciently yielding to engage the upper edge ofthe bottle neck I8 and accommodate itself to the variations in shape ofthe bottle neck unavoidable in mass production, thereby securing a goodseal under moderate pressure. The effectiveness of the seal can besomewhat further enhanced by forming a small bead at4Il in the bottominner edge of the flange 34. Because the process of glass manufacturewill leave a slight curvature in the surface of the glass indicated at42 in Figure 2, as distinguished from a sharp edge, the inclined portion36 will tend to get a bearing against the glass along a lineintermediate between the bead 40 and the weld at 38.

The particular conguration of the cap 24, especially when'the materialis polyethylene, enables a user to dispense medicament with acceptableaccuracy and much greater speed. than has been possible in the past.With the ordinary elongated rubber bulb, either tapered or tubular, themechanical resistance of the bulb to distortion, and the forces exertedby the distorted bulb to bringit back to its original shape, are usuallyample to aspirate the liquid, but not materially greater than that. Thisinvolves forces so small that no conscious muscular effort is requiredof the user to collapse the bulb completely and aspirate a much largerquantity of liquid than is desired.

With a dropper assembly according to the invention, pressure with thetip of a thumb or linger on the center of the dome 28 produces i'lrst alsmall central dimple, best deiined geometrically by everting a smallcentral area centered around the axis ofthe dropper assembly asindicated at 44 in Figure 2, and additional pressure enlarges the dimpleinto a position as indicated at 46 and 48 in Figure'2. In many instancesWhere a dropper is used to administer a charge that should be madeaccurate within 20 or 25%, depression to a predetermined degree willlift the desired amount of liquid into the pipette with -an entirelysatisfactory degree of accuracy. As the dimple grows larger, the area ofcontact between the finger and the dome increases, and the forceincreases also. When the desired liquid charge has been collected in thepipette, the dropper assembly is removed from the neck of the bottle andused in the usual manner.

Others may readily adapt the invention for use under various conditionsof service by employing one or more of the novel features involved, orequivalents thereof. A popular small size for such a dropper is with theannulus 26 about onehalf inch in inside diameter, but much larger sizeswork well also. As at present advisedV withA respect to the apparentscope of my invention, I desire to claim the followingA subject matter.

I claim:

l. In a medicine dropper assembly,y in' combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by water; aspirating means defining an enclosedenlargement of the space inside said pipette; said enlargement beingIabove said pipette and in open communication with the upper endthereof; the lower end of said pipette remaining open; said aspiratingmeans normally having maximum internal volume; and resilient restoringmeans resisting decrease of volume by deformation of said aspiratingmeans; whereby volume reduction followed by release, with the lower endof the pipette immersed, will draw into said pipette a Volume. of liquidsubstantially equal to the initial decrease; said resilient restoringmeans opposing decrease of volume with a force that increases at asubstantial rate throughout the available range of decrease; whereby theuser can pick up a preselected volume of liquid without ocularinspection by using the maximum force exerted for deformation as asensory gauge of quantity; said aspirating means being a cap of the sametype plastic as said pipette; said aspirating means including athin-walled outwardly concave spherical dome, evertable inwardly forvolume reduction; whereby a finger used to reduce the internal volume bypressing on said dome, is subjected to contact over progressivelyincreasing areas as the volume is reduced, and the tactile sense ofcontact area is also available to guide the user in securing apredetermined volume without ocular inspection; the resilient wall ofsaid dome constituting said restoring means; said pipette having a topange substantially normal to the pipette axis and extending radially outbeyond the pipette wall aV distance at least equal to the pipetteradius; the outer edge of said flange being fused or welded to anadjacent annular .portion of said aspirating means; said flange havingan annular conical portion inside and adjacent its peripheral weld,offsetting the Weld above the plane of the rest of the flange; means forclamping said pipette and. aspirating means against the lip of abottleneck by axial pressure applied to the periphery of said flange;said aspirating means havingr an annular abutment limiting axialdistortion of said conical flange portion; said abutment beingpositioned to engage said flange along a circular contact line spacedradially inward from the line of contact between said flange and saidbottle neck; saidv clamping means having screw-threaded engagement withsaid bottle neck and an inwardly-directed il'ange overlying said pipetteflange; and resilient means in the nature of a shallow external groovein said aspirating means and an axially facing annular abutment deningtheA upper edge of said groove, for engaging the inner edge of saidinwardly directed flange and holding said clamping means and aspiratingmeans assembled when removed from said bottle neck.

2. In a medicine dropper assembly, in combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by Water; aspirating means defining an enclosedenlargement of the space inside said pipette; said enlargement beingabove said pipette and in open communication with the upper end thereof;said aspirating means normally having maximum internal volume; theYlower end of said pipette remaining open; said aspirating means being apolyethylene plastic cap including a thin-walled outwardly concavespherical dome, evertable inwardly for volume reduction; said pipettehaving a top flange substantially normal to the pipette axis andextending radially out beyond the pipette wall a distance at least equalto the pipette radius; said plastic cap having a radial annular portionof' equal diameter of said pipette flange the outer edge of said flangebeing fused or welded to said annular portion of said aspirating means.

3. In a medicine dropper assembly, in combination: a pipette; saidpipette being of poly'- ethylene plastic of a type chemically inert tooil and not wetted by water; aspirating means defining an enclosedenlargement of the space inside said pipette; said enlargement beingabove said pipette and in open communication with the. upper endthereof; said aspirating means normally having maximum internal volume;the lower end of said pipette remaining open; said aspirating meansbeing a plastic cap including a thin-walled outwardly concave sphericaldome, evertable inwardly for volume reduction; said pipette having a topflange substantially normal to the pipette axis and extending radiallyout beyond the pipette wall a distance at least equal to the pipetteradius; the outer edge of said ange being fused or welded to an adjacentannular portion of said aspirating means; said flange having an annularconical portion adjacent its peripheral weld, offsetting the weld abovethe plane of the rest of the flange; means for clamping said pipette andaspirating means against the lip of a bottleneck by axial pressureapplied at the periphery of said flange with the bottle neck in annularcontact with said conical flange portion.

4. In a medicine. dropper assembly, in combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by water; .aspirating means de iining an enclosedenlargement ofthe space inside said pipette; said enlargement beingrabove said pipette and in open communication with the upper end thereof;said aspirating means normally having maximum internal Volume; the lowerend of said pipette remaining open; said aspirating means being aplastic cap including a thin-walled outwardly concave spherical dome,evertable inwardly for volume reduction; said pipette having a topilange substantially normal to the pipette axis and extending radiallyout beyond the pipette wall a distance at least equal to the pipetteradius; the outer edge of said flange being fused or welded to anadjacent annular `portion of said aspirating means; said flange havingan annular conical portion adjacent its peripheral weld, offsetting theweld above the plane of the rest of the flange; means for clamping saidpipette and aspirating means against the lip of a bottleneck by axialpressure applied at the periphery of said flange with the bottleneck inannular contact with said conical flange portion; said aspirating meanshaving an annular abutment limiting distortion of said conical llangeportion.

5. In a medicine dropper assembly, in combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by Water; aspirating means defining an enclosedenlargement of the space inside said pipette; said enlargement beingabove said pipette and in open communication with the upper end thereof;said aspirating means normally having maximum internal volume; the lowerend of said pipette remaining open; said aspirating means being aplastic cap including a thin-walled outwardly concave spherical dome,evertable inwardly for volume reduction; said pipette having a topflange substantially normal to the pipette axis and extending radiallyout beyond the pipette wall a dista-nce at least equal to the pipetteradius; the outer edge of said flange being fused or Welded to anadjacent annular portion of Said aspirating means; said flange having anannular conical portion adjacent its peripheral weld, offsetting theweld above the plane of the rest of the flange; means for clamping saidpipette and aspirating means against the lip of a bottleneck by axialpressure applied at the periphery of said ilange with the bottleneck inannular contact with said conical flange portion; said aspirating meanshaving an annular abutment limiting distortion of said conical flangeportion; said abutment being positioned to engage said ilange along acircular contact line spaced radially inward from the line of contactbetween said flange and said bottle neck.

6. In a medicine dropper assembly, in combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by water; aspirating means defining an enclosedenlargement of the space inside said pipette; said enlargement beingabove said pipette and in open communication with the upper end thereof;said aspirating means normally having maximum internal volume; the lowerend of said pipette remaining open; said aspirating means being aplastic cap including a thin-walled outwardly concave spherical dome,evertable inwardly for volume reduction; said pipette having a topflange substantially normal to the pipette axis and extending radiallyout beyond the pipette wall a distance at least equal to the pipetteradius; the outer edge of said flange being fused or welded to anadjacent annular portion of said aspirating means; said ange having anannular conical portion adjacent its peripheral weld, offsetting theWeld above the plane of the rest of the flange; means for clamping saidpipette and aspirating means against the lip of a bottleneck by axialpressure applied at the periphery of said flange with the bottleneck inannular contact with said conical flange portion; said aspirating meanshaving an annular abutment limiting distortion of said conical flangeportion; said abutment being positioned to engage said flange along acircular contact line spaced radially inward from the line of contactbetween said flange and said bottle neck; said clamping means havingscrew-threaded engagement with said bottle neck and an inwardly-directedflange overlying said pipette flange.

7. In a medicine dropper assembly, in combination: a pipette; saidpipette being of polyethylene plastic of a type chemically inert to oiland not wetted by water; aspirating means dening an enclosed enlargementof the space inside said pipette; said enlargement being above saidpipette and in open communication with the upper end thereof; saidaspirating means normally having maximum internal volume; the lower endof said pipette remaining open; said aspirating means being a plasticcap including a thin-walled out- Wardly concave spherical dome,evertable inwardly for volume reduction; said pipette having a topflange substantially normal to the pipette axis and extending radiallyout beyond the pipette wall a distance at least equal to the pipetteradius; the outer edge of said ange being fused or welded to an adjacentannular portion of said aspirating means; said flange having an annularconical portion adjacent its peripheral weld, offsetting the weld abovethe plane of the rest of the flange; means for clamping said pipette andasiprating means against the lip of a bottle neck by axial pressureapplied at the periphery of said flange with the bottle neck in annularcontact with said conical flange portion; said aspirating means havingan annular abutment limiting distortion of said conical flange portion;said abutment being positioned to engage said flange along a circularcontact line spaced radially inward from the line of contact betweensaid flange land said bottle neck; said clamping means havingscrew-threaded engagement with said bottle neck and an inwardly-directedflange overlying said pipette flange; and means in the nature of anexternal groove in said aspirating means and a resilient annularabutment defining the upper edge of said groove, for engaging the inneredge of said inwardly directed flange and holding said clamping meansand aspirating means assembled when removed from said bottleneck.

MACK R. FIELDS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date' 941,489 Beverly Nov. 30, 1909 2,105,202 Root et al Jan. 1l,1938 2,156,112 Dykema Apr. 25, 1939 2,311,367 "Chambers Feb. 16, 1943FOREIGN PATENTS Number Country Date 395,263 Great Britain July 13, 1933

